88 



PROCEEDINGS OF THE NATIONAL MUSEUM 



VOL. 81 



the surface, is a zone where there are few acanthostyles, instead 

 tornotes (subtylotes with hastate ends) in bundles and in confusion. 

 Histological details: Some at least of the flagellate chambers are 

 about 18/A in diameter. Throughout the sponge, but especially in the 

 ectosomal regions, there are abundant dark blue spiral microbes, 

 4/i, or 5fx long and about i^/x thick, very probably symbionts, and 

 certainly responsible for the blue color of the sponge. Bowerbank's 

 nymeniacidon gelatinosa (1866, p. 22-2, probably a Laxosuherites) 

 and a sponge, perhaps identical, which Carter (1882, p. 355) identi- 

 fied as Terpios coenda, have very similar color and symbionts. Car- 

 ter called these microbes HypTieotnx coerula. Topsent (1900, p. 199) 

 says that he submitted them to M. Lignier, professor of botany at 

 the University of Caen, who identified them as Beggiatoa alha var. 



Figure 51. — HymcnamplUastra ryanocrypta de liaubenfels : A-D, 

 X 300 ; others, X 1,333. H, one of the peculiar microscleres in end 

 view 



^nofrina Cohn. Recent taxonomic botany does not admit any colored 

 forms to the genus Beggiatoa. 



Principal spicules, acanthostyles (fig. 51, ^, 5) ; size, lO/x by 75jti 

 to 13/A by 280jti. Ectosomal spicules, tornotes (fig. 51, G) ; size, Sju 

 by 160/A to 3/x by 170/a. Microscleres, amphiasters (fig. 51, D-H) ; 

 length, 10/x to ll/i. 



Remarks. — The amphiasters are located abundantly throughout 

 the sponge and might be regarded as greatly modified birotulates, 

 but oftenest they closely resemble desmas. In one place in this 

 sponge were found some anchorate isochelas 26)u, long, some others 36ju, 

 long, and some sigmas about 16|U, long. From their exceedingly local 

 distribution, these would seem branded as foreign inclusions, but 

 they are worthy of mention in view of the indicated relationships. 



This form is obviously most clearly related to Eyinetrochota 

 Totula Topsent (1904, p. 168), type species of and only species in the 



